user.py

from hashlib import md5
from typing import NamedTuple, Optional

from aiopg import Connection


class User(NamedTuple):
    id: int
    first_name: str
    middle_name: Optional[str]
    last_name: str
    username: str
    pwd_hash: str
    is_admin: bool

    @classmethod
    def from_raw(cls, raw: tuple):
        return cls(*raw) if raw else None

    @staticmethod
    async def get(conn: Connection, id_: int):
        async with conn.cursor() as cur:
            await cur.execute(
                'SELECT id, first_name, middle_name, last_name, '
                'username, pwd_hash, is_admin FROM users WHERE id = %s',
                (id_,),
            )
            return User.from_raw(await cur.fetchone())

    @staticmethod
    async def get_by_username(conn: Connection, username: str):
        async with conn.cursor() as cur:
            await cur.execute(
                'SELECT id, first_name, middle_name, last_name, '
                'username, pwd_hash, is_admin FROM users WHERE username = %s',
                (username,),
            )
            return User.from_raw(await cur.fetchone())

    def check_password(self, password: str):
        return self.pwd_hash == md5(password.encode('utf-8')).hexdigest()